Complex Cracking in LF-ERW Pipe

Pipeline operators often employ various techniques to ensure the safety of their pipeline systems, including inline inspection (ILI)A method used to assess the the integrity and condition of pipelines. It involves the use of specialized tools that are inserted into the pipeline and propelled… and non-destructive examination (NDE)Refers to a range of techniques and methods used to assess the integrity, quality, and properties of materials, components, or structures without causing damage…. However, detecting and characterizing complex cracks, such as hook cracks, in low-frequency electric resistance welded (LF-ERW) pipes pose significant challenges. These challenges are exacerbated by the limitations in the performance specifications of available ILI tools. This is particularly true for small-diameter pipes, and the complexity of crackA fracture or discontinuity in the wall of a pipeline, where the material is separated or broken, potentially compromising the integrity and safety of the pipel… geometries. Hook cracks are difficult to detectTo sense or obtain a measurable indication from a feature. and size accurately due to their non-radial orientation and the presence of impurities in vintage pipelines.

In December 2021, a high-resolution axial crack inspectionThe systematic process of visually examining, testing, or monitoring pipeline components to assess their condition, integrity, and compliance with regulatory re… was conducted on a 6" pipeline constructed before 1970. The inspection revealed numerous anomalies, including hook cracks, which standard ILI tools struggled to accurately size and characterizeTo assign characteristics to a pipeline anomaly or feature based on its classification. due to their complex geometries and the small diameter of the pipeline

To address this challenge, NDT Global, in collaboration with Phillips 66, developed a novel approach to identifying and sizing hook cracks.

The project was structured in two steps:

• Step 1: ILI Data Signal Pattern Analysis

  • Analysis of ILI data patterns based on NDERefers to a range of techniques and methods used to assess the integrity, quality, and properties of materials, components, or structures without causing damage… results to identify and categorize complex cracking

  • Implementation of pattern recognition techniques to differentiate between various types of crackA fracture or discontinuity in the wall of a pipeline, where the material is separated or broken, potentially compromising the integrity and safety of the pipel… geometries

• Step 2: Field VerificationThe process of confirming or verifying that an inline inspection (ILI) meets specific requirements, standards, or expectations. It involves assessing and evalua… and Methodology Validation

  • Validation of the pattern recognition methodology through in-ditch NDERefers to a range of techniques and methods used to assess the integrity, quality, and properties of materials, components, or structures without causing damage… and field verificationThe process of confirming or verifying that an inline inspection (ILI) meets specific requirements, standards, or expectations. It involves assessing and evalua…

  • Application of advanced signal analysis to correlate ILI data with actual crackA fracture or discontinuity in the wall of a pipeline, where the material is separated or broken, potentially compromising the integrity and safety of the pipel… characteristics verified in the field

The innovative approach combined years of accumulated knowledge and advanced NDERefers to a range of techniques and methods used to assess the integrity, quality, and properties of materials, components, or structures without causing damage… techniques, including shear wave UTSystems used in non-destructive testing that utilize sound waves to detect, identify, and measure anomalies within a pipeline integrity test or management progr… and phased array UT, to improve the accuracy of crackA fracture or discontinuity in the wall of a pipeline, where the material is separated or broken, potentially compromising the integrity and safety of the pipel… detection and sizing. This method also involved calibrating the approach using destructive testing during lab analysis.

→ Enhanced crack detection: The new approach enabled the identification of patterns in ILI data that indicated the presence of hook cracks. This resulted in more accurate detection of complex crackA fracture or discontinuity in the wall of a pipeline, where the material is separated or broken, potentially compromising the integrity and safety of the pipel… geometries that traditional ILI tools would often miss or undersize

→ Field validation: The validation process confirmed the reliability of the pattern recognition methodology, with a significant percentage of field-verified anomalies matching the identified patterns in the ILI data

→ Informed integrityThe capability of a pipeline to perform its intended function safely and reliably throughout its life. It includes a range of factors, including the structural … management: The systematic method developed from this research has been integrated into the Integrity Management ProgramA documented set of policies, processes, and procedures implemented by operators to ensure the safe, reliable, and efficient operation of pipelines throughout t… (IMP), allowing for better prioritization and management of pipeline integrity threats